Unprocessed red meat in the dietary treatment of obesity: a randomized controlled trial of beef supplementation during weight maintenance after successful weight loss

Liver Fat Accumulation Is Associated With Increased Insulin Secretion Independent of Total, Visceral, and Pancreatic Fat

CONTEXT

Studies in heterogeneous groups of people with respect to sex, body mass index (BMI), and glycemic status (normoglycemia, impaired glucose tolerance, diabetes), indicate no relationship between liver fat accumulation and pancreatic insulin secretion.

OBJECTIVE

This work aimed to better understand the association of liver fat with insulin secretion.

METHODS

A cross-sectional analysis was conducted of 61 men with abdominal obesity who had high liver fat (HLF, ≥ 5.6% by magnetic resonance spectroscopy, n = 28) or low liver fat (LLF, n = 33), but were balanced on BMI, total body fat, visceral adipose tissue (VAT), and pancreatic fat. A frequently sampled 5-hour oral glucose tolerance test with 11 samples, in conjunction with mathematical modeling, was used to compute indices of insulin sensitivity and insulin secretion (oral minimal model).

RESULTS

Compared to individuals with LLF, those with HLF had significantly greater fasting glucose, insulin, C-peptide, and triglycerides; lower high-density lipoprotein cholesterol; but similar glycated hemoglobin A1c. Areas under the 5-hour curve for glucose, insulin, and C-peptide were greater in the HLF group than the LLF group (by ∼10%, ∼38%, and ∼28%, respectively); fasting and total postprandial insulin secretion rates were approximately 37% and approximately 50% greater, respectively (all P < .05); whereas the insulinogenic index was not different. HLF participants had lower whole-body and hepatic insulin sensitivity, disposition index, and total insulin clearance than LLF participants (all P < .05).

CONCLUSION

Accumulation of liver fat is associated with increased insulin secretion independently of total adiposity, abdominal fat distribution, and pancreatic fat. Thereby, hyperinsulinemia in fatty liver disease is partly because of insulin hypersecretion and partly because of impaired insulin clearance.

Red Meat Amino Acids for Beginners: A Narrative Review

Meat is a major source of dietary protein and fat across the globe. Red and white meat are the major terms consumers use to refer to types of meat; however, these terms do not fully encompass the range of nutrients provided by meat sources. Red meat refers to meat from mammalian skeletal muscle, while white meat refers to poultry. Red and white meat both provide a wide range of nutritional components in the context of fatty acids, amino acids and micronutrients. Importantly, it has been demonstrated that amino acid profiles differ between red meat and white meat as well as between different sources of red meat. Red meat is a complete source of dietary amino acids, meaning it contains all essential amino acids (EAAs), and in addition, it contains all the non-essential amino acids (NEAAs). Red meat is also the most abundant source of bioavailable heme-iron essential for muscle growth and cardiovascular health. Red meat has been indicated as a major contributor to the rising incidence of metabolic disorders and even colorectal cancer. However, it is important to note that while red meat consumption is linked to these conditions, it is typically the overconsumption of red meat that is associated with obesity and other metabolic symptoms. Similarly, the preparation of red meat is a key factor in its link to colorectal cancer as some methods of preparation produce carcinogens while others do not. Finally, red meat may also be situationally more beneficial to some groups than others, particularly in the cases of sex and aging. For pregnant women, increases in red meat consumption may be beneficial to increase the intake of semi-essential amino acids, while in the elderly, increases in red meat consumption may better preserve muscle mass compared with other dietary protein sources.

Beef Consumption and Cardiovascular Disease Risk Factors: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background

Results from observational studies suggest associations of red meat intake with increased risk of cardiovascular disease (CVD); however, RCTs have not clearly demonstrated a link between red meat consumption and CVD risk factors. Further, the specific effects of beef, the most consumed red meat in the United States, have not been extensively investigated.

Objectives

This study aimed to perform a systematic review and meta-analysis of RCT data evaluating the effects of minimally or unprocessed beef intake on CVD risk factors in adults.

Methods

A search of the literature was conducted using PubMed and CENTRAL databases. RCTs in adults that provided diets with fresh or minimally processed beef were included. Data were extracted, and pooled estimates from random-effects models were expressed as standardized mean differences (SMDs) between the beef intervention and comparator intervention with less or no beef. Sensitivity and subgroup analyses were also performed.

Results

Twenty relevant RCTs that met the criteria were included. Beef intake did not impact blood pressure or most lipoprotein-related variables, including total cholesterol, HDL-cholesterol, triglycerides, non-HDL-cholesterol, apolipoprotein A or B, and VLDL-cholesterol. Beef consumption had a small but significant effect on LDL-cholesterol (0.11; 95% CI: 0.008, 0.20; P = 0.03), corresponding to ∼2.7 mg/dL higher LDL-cholesterol in diets containing more beef than that in low-beef or -o beef comparator diets. Sensitivity analyses show this effect was lost when 1 influential study was removed.

Conclusions

Daily unprocessed beef intake do not significantly affect most blood lipids, apolipoproteins, or blood pressures, except for a small increase in LDL-cholesterol compared with diets with less or no beef. Thus, there may be other factors influencing the association of red meat and beef on CVD risk that deserve further investigation.This study was registered at INPLASY as 202420013.

The utilisation of agricultural by-products in processed meat products: Effects on physicochemical, nutritional and sensory quality - Invited Review

Several plant-based materials are discarded by the food industry due to oversupply, lack of transport, and inappropriate storage. These materials contain valuable essential micronutrients such as minerals, vitamins and bioactive components (e.g., polyphenol, tocopherols, ascorbic acid, carotenoids) with antioxidant, antimicrobial, and anti-inflammatory effects, among others. In the context of making our agriculture-food based economy more circular and sustainable, and to develop foods with clean labels and less E-numbers, fruits, vegetables, yams, cereal distillers, oilseeds and other plant by-products could be utilised and upcycled back into new food formulations. Meat products are a particularly suitable matrix for this purpose, due to their susceptibility to lipid and protein oxidation and microbial spoilage (which shorten their shelf life). This review brings together the latest (2020-23) reformulation efforts, preservative methods and other innovative pathways, including studies on by-products as plant-based additives and bio-actives. It will cover the use of plant-based by-products as natural additives into production of processed meat products such as burgers, fermented meats and sausages, produced from ruminant and monogastric animals (except poultry). The extraction methods, inclusion levels, processing methods used and the quality of the resulting meat products will be reported, including preservative effects (microbial growth, oxidative stability and shelf life) and effects on instrumental, nutritional and sensory quality. Furthermore, it will also critically discuss the gaps identified, recommendation of the most promising ingredients for quality enhancement, and provide directions for future research.

High- and normal-protein diets improve body composition and glucose control in adults with type 2 diabetes: a randomized trial

OBJECTIVE

Weight loss of ≥10% improves glucose control and may remit type 2 diabetes (T2D). High-protein (HP) diets are commonly used for weight loss, but whether protein sources, especially red meat, impact weight loss-induced T2D management is unknown. This trial compared an HP diet including beef and a normal-protein (NP) diet without red meat for weight loss, body composition changes, and glucose control in individuals with T2D.

METHODS

A total of 106 adults (80 female) with T2D consumed an HP (40% protein) diet with ≥4 weekly servings of lean beef or an NP (21% protein) diet excluding red meat during a 52-week weight loss intervention. Body weight, body composition, and cardiometabolic parameters were measured before and after intervention.

RESULTS

Weight loss was not different between the HP (-10.2 ± 1.6 kg) and NP (-12.7 ± 4.8 kg, p = 0.336) groups. Both groups reduced fat mass and increased fat-free mass percent. Hemoglobin A1c, glucose, insulin, insulin resistance, blood pressure, and triglycerides improved, with no differences between groups.

CONCLUSIONS

The lack of observed effects of dietary protein and red meat consumption on weight loss and improved cardiometabolic health suggests that achieved weight loss, rather than diet composition, should be the principal target of dietary interventions for T2D management.